The machining or grinding of elongate and slender parts has been a longstanding problem. The pressure of a cutting tool or a grinding wheel near the middle of a rotating part supported at the respective ends on centers will cause a bending of the part and prevent an accurate removal of metal. Accordingly, work supports have been provided on lathes to support the middle of a long part while it is being machined.
However, in a transfer machine which is moving parts along an automation line, the use of these work supports is difficult if not impossible due to the clearance needed between the spaced centers for moving the parts from one work station to another down the transfer line. A so-called "lift and carry" mechanism lifts a part from one station, carries it to the next station, and then returns to the first station from which it receives a part.
It is an object of the present invention to provide a system and mechanism for supporting elongate, slender parts between centers for rotation in a machining or grinding function at the same time telescoping a chuck over the part to a position near a portion to be machined and supporting the part at that position in a part-gripping chuck which will also drive the part in rotation. Upon completion of the machining operation, the support chuck is retracted, the centers retracted, and the part transferred down the line to the next work station where it is again mounted between centers and chucked between the ends for a subsequent operation.
In order to finish both ends of the part, the work-swallowing chucks can be positioned at opposite ends of the part. For example, during some station locations, viewed along the direction of travel transverse to the axis of the parts, the chucks can be on the left-hand end of the parts, and, at subsequent stations, the chucks can be on the right-hand end.
A further object is a work support for a slender part which is relatively inexpensive to manufacture and yet completely retractable from the work path in the transfer line.
Other objects and features of the invention will be apparent in the following description and claims taken with the accompanying drawings in which the invention is described together with the details of the manner and process of using it to enable persons skilled in the art to utilize the invention, all in connection with the best mode presently contemplated for the practice of the invention.